With conventional automotive vehicles, one or more keys are often shared between any number of drivers. For example, the parents of a teenager (or young adult) that is old enough to drive may share the keys for the vehicle with the teenager. The vehicle may be equipped with various safety and/or driver notification features that may be enabled/disabled via a user interface based on the driver's needs. However, in some circumstances, the parent may not wish to have the various safety-related features disabled or altered by the teenager. The parent may enable the safety features and select desired settings prior to allowing the teenager to drive the vehicle, however there is no guarantee that the teenager will keep the safety features enabled and using the same settings while driving the vehicle. Conventional vehicles fail to give parents, or other such primary drivers, the option of preventing teenagers eligible to drive or other such secondary drivers from disabling or altering the settings of safety features.
U.S. Pat. No. US 8,258,939, issued on Sep. 4, 2012, is co-owned by the owner of the present patent application and teaches a device for controlling one or more vehicle features for a primary driver and a secondary driver. The device comprises a controller receiving a driver status signal from an ignition key device, the driver status signal indicative of the driver being either a primary driver or a secondary driver. The controller controls one or more vehicle features and prevent the vehicle features from being disabled when the driver status signal indicates that the driver of the vehicle is a secondary driver. Example safety-related vehicle features that are controlled in this way include Forward Collision Warning, Lane Departure Warning, and Electronic Stability Control.
Adaptive Cruise Control (ACC) systems use an on-board sensor (usually radar or lidar) to detect the distance between the host vehicle and a vehicle ahead of the host (the lead vehicle) and the relative speed difference between the vehicles. The system then automatically adjusts the speed of the host vehicle to keep it at a pre-set distance behind the lead vehicle, even in most fog and rain conditions. Typically, the host vehicle driver can set a desired/minimum following distance and/or a time gap to be maintained between vehicles. The ACC generates automatic interventions in the powertrain and/or braking systems of the host vehicle to slow the vehicle as necessary to maintain the selected minimum following distance. Some ACC systems also generate a driver alert or warning (usually audible), and the driver may be able to select the time prior to reaching the minimum following distance that the warning will be generated, typically in the range of approximately 1 to 3 seconds
Some ACC systems also can determine how fast the host vehicle is approaching the lead vehicle. For example, when approaching a lead vehicle at a high rate of speed, the system will activate sooner than when approaching slower.